New thermal‐petrologic models of subduction zones are used to test the hypothesis that intermediate‐depth intraslab earthquakes linked metamorphic dehydration reactions in subducting oceanic crust and mantle. We show there is a correlation between patterns seismicity locations predicted hydrous minerals: Earthquakes occur slabs where expected, they absent from parts be anhydrous. propose plate can consist four petrologically seismically distinct layers: (1) hydrated, fine‐grained basaltic...

We present a new compilation of physical properties minerals relevant to subduction zones and phase diagrams for mid‐ocean ridge basalt, lherzolite, depleted harzburgite, serpentinite. use these data calculate H 2 O content, density seismic wave speeds zone rocks. These calculations provide basis evaluating the factory, including (1) presence hydrous phases distribution within zone; (2) densification subducting slab resultant effects on measured gravity shape; (3) variations in resulting...

Unconventional oil and gas production provides a rapidly growing energy source; however, high-production states in the United States, such as Oklahoma, face sharply rising numbers of earthquakes. Subsurface pressure data required to unequivocally link earthquakes wastewater injection are rarely accessible. Here we use seismicity hydrogeological models show that fluid migration from high-rate disposal wells Oklahoma is potentially responsible for largest swarm. Earthquake hypocenters occur...

Research Article| June 01, 2013 Potentially induced earthquakes in Oklahoma, USA: Links between wastewater injection and the 2011 Mw 5.7 earthquake sequence Katie M. Keranen; Keranen 1ConocoPhillips School of Geology Geophysics, University 100 E. Boyd Street, Norman, Oklahoma 73069, USA Search for other works by this author on: GSW Google Scholar Heather Savage; Savage 2Lamont-Doherty Earth Observatory Columbia University, PO Box 1000, 61 Route 9W, Palisades, New York 10964, Geoffrey A....

The location and motion of subducting plates relative to volcanic arcs provide a first‐order constraint on theories arc magmagenesis. We compile volcano‐specific subduction parameters for 33,000 km the global system at 839 centers, measuring depth top slab ( H ) beneath each volcano. compilation also includes estimates strike dip, incoming plate velocity, age, all available in accompanying auxiliary material. geometry is contoured from surface Wadati‐Benioff zones (WBZs) variety teleseismic...

A recent dramatic increase in seismicity the midwestern United States may be related to increases deep wastewater injection. Here, we demonstrate that areas with suspected anthropogenic earthquakes are also more susceptible earthquake-triggering from natural transient stresses generated by seismic waves of large remote earthquakes. Enhanced triggering susceptibility suggests presence critically loaded faults and potentially high fluid pressures. Sensitivity is most clearly seen sites a long...

Abstract In November 2011, a M 5.0 earthquake occurred less than day before 5.7 near Prague, Oklahoma, which may have promoted failure of the mainshock and thousands aftershocks along Wilzetta fault, including aftershock. The foreshock in close proximity to active fluid injection wells; can cause buildup pore pressure, decrease fault strength, induce earthquakes. Keranen et al . [ ] links with injection, but relationship between successive events has not been investigated. Here we examine...

An Excel macro to calculate mineral and rock physical properties at elevated pressure temperature is presented. The workbook includes an expandable database of parameters for 52 rock‐forming minerals stable high pressures temperatures. For these the elastic moduli, densities, seismic velocities, H 2 O contents are calculated any specified P T conditions, using basic thermodynamic relationships third‐order finite strain theory. modes suites rocks also specifiable, so that their predicted...

We use expressions for the cross‐correlation of stochastic surface waves originally derived by Aki (1957) to develop an algorithm determining inter‐station phase‐velocity measurements from continuous seismic data. In frequency domain, cross correlation azimuthally isotropic noise is described a Bessel function, and we associate zeros in observed spectrum with function obtain estimates at discrete frequencies. Phase velocities this way several frequencies are joined form dispersion curve,...

In southern and central Alaska the subduction active volcanism of Aleutian zone give way to a broad plate boundary with mountain building strike‐slip faulting, where Yakutat terrane joins subducting Pacific plate. The interplay these tectonic elements can be best understood by considering entire region in three dimensions. We image three‐dimensional seismic velocity using abundant local earthquakes, supplemented source data. Crustal low‐velocity correlates basins. Denali fault is dominant...

We have detected dozens of previously unknown, moderate earthquakes beneath large glaciers. The seismic radiation from these is depleted at high frequencies, explaining their nondetection by traditional methods. Inverse modeling the long-period waveforms best-recorded earthquake, in southern Alaska, shows that source well represented stick-slip, downhill sliding a glacial ice mass. duration Alaska earthquake 30 to 60 seconds, about 15 times longer than for regular tectonic similar magnitude.

Combined analysis of high-resolution seismic images the Alaska and Cascadia subduction zones reveals where metamorphic fl uids are released. Both show subducted oceanic crust as a dipping low-velocity layer with clear termination depth. However, in is thicker (15-20 km compared to 8 km) terminates at greater depth (120 com- pared 40 than Cascadia. Based on reaction estimates geodynamic models, we demonstrate that corresponds eclogitization triggered by dehydration water-bearing minerals,...

Anelastic loss of seismic wave energy, or attenuation (1/ Q ), provides a proxy for temperature under certain conditions. The structure the upper mantle beneath central Alaska is imaged here at high resolution, an active subduction zone where arc volcanism absent, to investigate thermal structure. recent Broadband Experiment Across Range (BEAAR) first dense broadband coverage this region. spectra P and SH waves regional earthquakes are inverted path averaged operators between 0.5 20 Hz,...

Abstract To interpret seismic images, rock velocities need to be calculated at elevated pressure and temperature for arbitrary compositions. This technical report describes an algorithm, software, data make such calculations from the physical properties of minerals. It updates a previous compilation Excel ® spreadsheet includes new MATLAB tools calculations. The database 60 mineral end‐members all parameters needed estimate density elastic moduli many crustal mantle rocks conditions relevant...

Abstract The oceanic crust that enters a subduction zone is generally recycled to great depth. In rare and punctuated episodes, however, blueschists eclogites derived from subducted are exhumed. Compilations of the maximum pressure‐temperature conditions in exhumed rocks indicate significantly warmer than those predicted by thermal models. This could be due preferential exhumation hotter promote greater fluid productivity, mobility, buoyancy. Alternatively, models might underestimate forearc...

Variations in crustal thickness from the Great Plains of Kansas, across Colorado Rocky Mountains, and into eastern Plateau are determined by receiver function analysis broadband teleseismic P waveforms recorded during 1992 Mountain Front Program for Array Seismic Studies Continental Lithosphere (PASSCAL) experiment. The functions calculated using a time domain deconvolution approach interpreted terms single layer, with grid‐search comparison observed synthetics. average thicknesses these...